Everyone wants to be a king. Some of us want to be the king of our workplace, or the king of our house. Some of us want to be the king of our fantasy football league, or the king of our neighborhood's Christmas light displays. Some of us treat the highway as our own little kingdom, demanding that our minions ask our permission before they change lanes or slow down.
Kings stand above everyone else, receiving praise and reverence from everyone around them. Nothing is withheld from kings, after all. They never come in second place, and they never have to acquiesce to another's needs.
It's good to be king.
Adam and Eve were God's appointed rulers of his kingdom. Unlike most kingdoms we see today, they had all the power a king had. They exercised ordained dominance over their territory. They named animals, ate their fill, and had almost no one to answer to. Almost.
There was still a King on his throne. With all their privileges, they still had a restriction — the tree of the knowledge of good and evil. The King knew what would happen if they ate of it. He was a good King, one who wasn't domineering, but loving. But they didn't care. They ate of its fruit, and they lost all they had been given. Their lowercase-t throne was ripped out from under them.
From then on, human kings didn't stand a chance. Sin had infiltrated the kingdom. The Earth, their delegated territory, was compromised.